Wave conversion



Sept. 3, 1946. H. TUNlcK WAVE CONVERSION Filed June 16, 1942 2 Sheets-Sheet 1l Sept. 3, 1946. H. 'ruNrlcK wvE CONVERSION 2 Sheets-Sheet 2 Filed June 1e, 1942 Ow wm Hill- Zmventor nza' Gttorncg WOM Patented Sept. 3, 1946 WAVE ooNvEnsIoN Harry Tuniek, Rye, N. Y., assignor to Radio lCorporation of America, a corporation of Dela- Waffe Application J une 1.6, 1942, 'Serial N0. 447,225

27 (Jlallls. (Cl. Z50-15) My present invention relates to conversion of Waves of one frequency to waves of another frequency. My invention has particular application to radio relaying systems for relaying frequency or phase modulated Waves or, more generali angle modulated waves.

Some of the objects of my invention are, to improve radio relaying circuits, to provide radio relaying circuits which are substantially free 0f undesired frequency drifts, and `to `prov-ide radiorelaying circuit arrangements highly free of distortion and in Which the re-transmitted waves always bear a substantially `fixed relation in frequency to the received Wave or waves to b e relayed.

Other objects, advantages and features of'my invention will be apparent as the more detailed description thereof is given.

In the accompanyingdrawings:` t

Figurexl illustrates a radio relaying system in which the difference' frequency between received and roe-transmitted Waves is derived by frequency dividing the received Waves. Figure 1 also ernploys a local source -of oscillations used first, for heterodyning dov/n the received Waves and then, for heterodyning back, modified waves for retransmission.

Figure 2 is a modied form of Figure 1 in which the local heterodyning oscillator ,has been eliminated. i

Figure 3 is another form of my invention wherein one part of `,the received Waves is frequency divided and then combi-ned with another part of the received `Waves to produce a different frequency for retransmission, and

Figure 4 is a modified form of Figure 2.

Referring to Figure 1, ultra short waves are received upon the antenna 2 and fed through transmission line to amplifier 6. The waves received upon antenna 2 are assumed to be frequtncy or phase modulated or, more generally, angle modulated. For greater ease in explaining the invention of Figure 1, it shall be `assumed that the received waves have a mean or carrier frequency of 56) megacyeles and that the carrier has been modulated with one or more signals. Further, it is assumed that the maximum frequency swing of the carrier produced by maximum amplitude signal voltages is plus and minus 200 kilocycles.

It is to be clearly understood that these frequency values have been arbitrarily chosen and are illustrative only and are not to be `considered in any Way as limiting the present invention.

Part of the amplified energy from 'amplifier S 2 is fed through line sito frequency dividers and amplifiers lli so that the output thereof as illustrated is .5 me. in line i2. This frequency divided energy is further amplified and filtered in amplier I4.

Another porti-on of the output of` amplifier ii is fed to aV converter or heterodyning detector i6. Converter L6 is also supplied through transmission line i8 with heterodyning waves of a mean frequency of 600` `rnegacycles. This 660 mc. heterodyningwave may he derived, as shown, from a relati'veiy constant frequency osciilator 2i) and frequency multiplier 22.

Qi' the resulting beat frequencies in the output of converter i6, thediererice frequency or 10() megacycles fed through amplifier and filter 24 and thence -to asecond converter or heterodyning detector 2t which is also supplied with the divided energy .of `.5 rnc, from the output of amplifier i4 vthroirgh 'line 28.

`The upper side band produced in converter 25 is then selected by amplifier and filter 3B and for the `values vassumed this upper side band would havea mean frequencyfo-f 100.5 inegaoycles. This selected `upper side band from amplifier and lter 30 is then `fed to another converter 32 by way of line 3ft. Converter 3,2 is also supplied with 609 mc. locally generated Waves through line 3B. The output of converter `32 maythen befed to a filter and amplifier l3,8 through `'line 4D. Filter and amplifier 38 may be adjusted .and constructed so as to pass the meanldiiference .frequency or 499.5 megacycles to .the .re-transmitting antenna 42 by way of line .44. If desired, of course, may .be adjusted and constructed so as to pass the other orupper side band which lwould have as--its mean frequency 500.5 megacycles.

Also; it is to he understood that filter 3i) may be adjusted so as to pass 99.5 mc.. in line 3d and in that event nlteri could he adjusted so as to pass waves `having mean frequencies yof either 70.0.5 megacycles or 69.9.5 mega-cycles.

In the arrangement of .Figure l certain decided advantages obtain. First, it is to be noted that any changes in frequency of the local oscillator 29 prove substantially self-cancelling in the resultantoutputrsince waves der-lived from oscillator 2U rare employed in successive heterodyning processes. Thus,` `if the `oscillator' .frequency drifts, the -dr-ift is first lsubtracted and then added in the successive heterodyning processes and, hence, the final output is left unaffected by the drift. By means of the frequency .dividers .ha and converter 2b` the resulting 1re-transmitted frequency at 42 is different than that received. This 4difference in frequency, when either 499.5 or 500.5 mc. is re-transmitted, is equal to the frequency of the output of divider 10. Since the mean output frequency of divider 10 depends entirely upon the received wave, the re-transmitted Wave at 42 always bears a definite fixed relation with respect to the received wave at 2. The arrangement of Figure 1, therefore, oiers a decided advantage over installations wherein the difference frequency is obtained by an independent local oscillation generator whose frequency is entirely independent of the received or re-transmitted waves.

Figure l may be modified by connecting the input to divider 10, namely, line 0, to transmission line 44 choosing an appropriate division factor for the dividing apparatus. In this case, however, the constancy of the divider output would depend upon the constancy of the output.

in the output circuit of converter 32.

As illustrated in Figure 1, the dividing factor of divider 10 is seen to be 1000. Hence, the output in line 28 will not be a wave of constant frequency, but will be a Wave of .5 mc. plus and minus 200 cycles, assuming a maximum deviation of plus and minus .2 mc. in the received waves. This variation in frequency in line 28 may increase or decrease the resultant modulation at retransmitting antenna 42 by plus and minus 200 cycles, but since this is a very small amount relative t the signal modulation of plus and minus .2 megacydes it may be disregarded or neglected for all practical purposes.

The frequency dividers may be of the type described in, and follow the principles of frequency division of, the patents to M. G. Crosby Nos. 2,230,231 and 2,230,232. This is not only true of the divider I0 of Figure l, but is also true of he frequency dividers used in the other forms of my present invention about to be described, or, the dividers may follow the circuits and principles laid down by G. L. Beers in his U. S. Patent 2,356,201 dated August 22, 1944.

In the radio relaying system of Figure 2 assume,

for example, the received Wave picked up byanf tenna 200 has a mean frequency of 1000 megacycles and carries a maximum frequency swing of plus and minus .2 mc. The received waves arel fed through line 202 to amplifier 204. Part of the amplified waves are fed through line 206 to frequency dividers, amplifiers and filters 208 so that the mean frequency of the output thereof in line 210 is one megacycle. This one megacycle output is fed to a converter 212 which is also supplied with waves having a mean frequency of .1 mc. through line 214. The Wave energy in line 214 is derived from the signal and, more specifica ly, from amplifier 204 through line 216 and frequency dividers 218, 220 which may also include amplifying stages.

By the action of converter and filter 212, a wave of mean frequency of 1.1 mc. is filtered out in line 222 which is fed into converter, filter and amplifier 224. Converter 224 is also fed withV a Wave having a mean frequency of 500 mc. derived from divider 210. The 500 mc. wave is fed through line 226 to the converter 224. As a result of the converting and filtering action in 224 a wave of mean frequency of 501.1 mc. appears in line 220` which may then be multiplied in frequency multiplier 230 to 1002.2 megacycles, amplified in amplifier 232 and radiated by way of radiating antenna 234.

If desired in the modification 0f Figure 2, converter and filter 212 may be designed to feed 0.9 mc. into line 222 and the filter 224 may bedesigned to feed into line 228 498.9 mc. or in case 0.9 mc. is used in line 222, filter 224 may be arranged to pass either a wave having a mean frequency of 499.1 mc. or 500.9 mc. The frequency multiplier 230 may have a multiplying factor of two or any higher whole number, as desired. As suming a multiplying factor of two so that the frequency multiplier acts as a doubler, then, depending upon the input to multiplier 230, the mean frequency of the wave radiated by antenna 234 will be 997.8 megacycles or 1002.2 megacycles or 998.2 megacycles or 1001.8 megacycles.

In Figure 3, assume that a frequency modulated Wave having a mean or carrier frequency of 60 mc. is received upon the receiving antenna 300. The received Wave is amplified in amplifier 302 and fed to a converter or carrier suppression modulator 304 which is also supplied with waves having a mean frequency of .6 mc. through line 306. The wave energy in line 306 is derived from the received signal by means of the frequency dividers 308 and filters and amplifiers 310. Of the resulting side bands following from the action of converter 304 either the upper side band having a mean frequency of 59.4 mc. may be selected by lilter and amplifier 312 or the lower side band hav ing a 'mean frequency of 60.6 mc. The selected side band is fed through a transmission line 314 to amplifier 316 and then radiated by transmitting antenna 318.

In the system of Figure 3, amplifier 316 may include a frequency multiplier, such as a doubler, in which case the radiated frequency will have a mlean frequency of twice that appearing in line 3 4.

It is to be noted that in both Figures 2 and 3, the retransmitted wave must bear a fixed relationship to the received wave since all changes in frequency are derived from the received wave and are totally independent of any local oscillation generator freely operating at its own frequency.

The relay system of Figure 4 is somewhat similar to that shown in Figure 2. The wave frequencies marked upon Figure 4 are given by Way of example and obviously other values may be chosen. It may be assumed that the incoming wave has a mean frequency of 600 megacycles and that the maximum deviation in frequency produced by the strongest modulating signal is plus and minus 50 megacycles. The wave frequencies marked on Figure 4 indicate only the mean frequencies and do not show the effects of division and multiplication on the deviations which may readily be calculated from the values shown.

More specifically, in Figure 4 waves received upon antenna 400 are amplified at amplifier 402. Part of the amplified waves is divided in frequency dividers 404 and fed to a converter or heterodyning detector or modulator 405. A heterodying wave is also fed to the converter 406 through line 408 fed by dividers 410, 412 and 414, in turn energized by wave energy from amplifier 402 fed to the input of divider 410 through line 416. Filter 410 selects either the upper or lower side band of frequencies produced by converter 400 and the selected band of frequencies is fed to frequency multipliers, amplifier and filter 420, in turn energizing re-transmitting antenna 422.

Also in Figure 4 it is to be noted that all freely oscillating oscillators have been eliminated, as a consequence of which the retransmitted wave at 422 always bears a definite, fixed relation to the frequency of the input Wave received upon receiving antenna 400.

The frequency dividers in any of the modications described hereinabove vmay bemadein acz` cordance withthe principles set forth in the pat ents t0 M. G. Cr0Sby..NOS.2,230,23l; and12,230,232

orin the copending application of G..-L.. Beers.

Serial No. 430,588, filed` February 12,1942, now U. S. Patent 2,356,201. The frequency multipliers referred to hereinabove may beset upm accordance with the principles set forth inthe patent. to

C. W; Hansell No. 1,878,308. The reactance tube l frequency i control circuit `may follow the prin-il ciples set'forth in the patents `to M. G. Crosby Nos. 2,279,659, 2,279,660 and. 2,279,661.. `Amplitude limiting may Vnotonly be used inthe final` am pli-ner stages, but may .alsobe used in the intermedi-ate frequency amplifiers and in. the `initial amplifiers connected' to thefreceiving antennas aswell.. 1 1

Also, it isto be noted where frequencydividers` areemployed, the succeeding iiltersneednot have a pass` band Wide enough to-pass the Vinput to the divider. For example, in Figuregzfdivider 208'divides. downnot only the mean frequency received on antenna.V 202, but also vthe deviation. l This means that the filters in the output of V208 need be designed to pass only a band of 'frequencies substantially narrower than that vreceivednur'ion theantennaZlJ. f 1* Having thus described my invention, what `I 1. The method ofwave conversion- Which inA cludes heterodyning Waves. the frequency of which is to be changed, to an intermediate frequency, frequency dividing wave energy derived from said Waves, combining the frequency divided wave energy and the Waves of intermediate frequency and utilizingl the 'resultant Wave energy. 2. The method of converting Waves to another frequency which includesA heterodyning a part of the waves to be converted to an intermediate frequency, frequency dividing another part of the Waves to be converted to a lower frequency, cornbining the Waves of intermediate frequency andv thewaves resulting from-the division, selecting a portion of the combined Waves and heterodyning the selectedvportion to a desired frequency.

3. In a radio relay system, means for receiving angular velocity modulated Waves, a frequency divider for frequency dividing a part of thev received Waves, a. source of heterodyning oscillations, 4apparatus for combining said hetercdyning oscillations and another part. of the received waves to produce an intermediate frequency, means for and means for heterodyning the iiltered'waves to` a higher frequency with Waves derived Vfrom said' r source. -v

5.The method which includes frequcencyI dividing one portion of alternating ivaveenergy, frequency dividing to a greater degree another portion of said alternating wave energy, and combining the divided energies;

6. The method which includes frequency dividing `one part of alternatingY electrical wave 6, energy, frequency. dividing to a greater degreeV another part of thewave energy, heterodyning the'divided: energies, filtering the heterodyned energies and utilizing the .filtered energies;

7. The method which includes frequency dividing. one portion of alternating wave energy, frequency dividing to a greater degreeanother portion `of. said Wavev energy, heterodyning the divided waves, filtering the heterodyned waves f andirequency multiplying the filtered waves.

8. .Apparatus for relaying angle modulated' waves comprising a frequency divider for dividing one portion of the modulated waves, another frequency dividerv for frequencydividing to a greater degree another portion of the modulated Waves, means for heterodynlng the frequency divided Waves, a filter for ltering'the heterodyned Waves,`

and apparatus for utllizingthe filtered waves.

9; Apparatus as claimed in claim 8 char acterized bypthefact that a frequency multiplier is provided for frequency multiplying the filtered waves.

10. The method of Wave conversion which includes frequency dividing a portion of electrical waves to be converted, heterodyning the frequency divided waves and another portion of the Wavesto be converted, filtering the heterodyned Waves',` frequency multiplying the filtered Waves and utilizing the frequency multiplied'` waves.

1l. A radio relaying system comprising' means for receiving radio waves, means' for frequency dividing one portion of the receivedwaves, means for combining another portion of the. received Waves with the frequency divide-d Waves, aiilter forl filtering the combinedwaves, and a frequency multiplier for frequency multiplying the filtered Waves. 'I

12. The method which includes dividing the frequency of one portion of electrical Waves aridsuccessively heterodyning the frequency divided waves With 4Waves of different frequency resulting from frequency divisions of other portions of said wave energy.

13. The method which `includes frequency dividing one portion of' electrical wave energy to one frequencyifrequency dividing another portion of'said' electrical wave energy to. another frequency, hterodyn'ing the waves of dividedfre-i quericy, filtering the heterodyned WavesV and fre quenjcy multiplying the filtered waves.'

14. In aradio relay system.. means for receiving waves, a frequeneydivided. for frequency dividing a part of the ,received wai/'esa source of hetero-- dynirigA oscillations, apparatus for combining said l heterodyning oscillations and another part ofthe received waves to produce an intermediate ffrequency, meansfor heterodyning the frequency divided Waves andthe waves of intermediate frequency, and means for utilizing the lastf-Inen-A tioned heterodyned waves.

15. VInla radio relaying system, means for re"- ceiving high.` frequency waves, a source of heterodyning oscillations, means to` heterodynea part of the receivedwaves with waves from saidfsource so as. to produce an Vintermediate* frequency, a

frequency divider`A for frequency dividing another part of the received waves, means foi` combining the divided waves and waves of intermediate-fre quency, means for filtering the combined waves, and means for heteredyning the filtered Waves to a higherfrequency with waves-derived from said sourcel f 16. A relaying system for relaying phase orfrequency` modulated `Waves comprising a `source off tions, a converter for heterodyning together a portion of the output of said multiplier andanother portion of the output of said amplifier, apparatus for amplifying and filtering the output of said converter, another converter in which the output of said last-mentioned amplifier and filter and the output of said frequency divider are heterodyned together, an amplifier and filter coupled to the output of said last-mentioned converter," another converter `for heterodyning tgether another portion of the output of said fre-V quency multiplier and the output of said lastmentioned amplifier and filter, and a filter and amplifier for filtering and amplifying the output of said last-mentioned converter.

1'7. A relaying system for phase or frequency modulated waves comprising an antenna for picking up phase or frequency modulated waves, an amplifier for amplifying the Waves so picked up, a frequency divided for dividing a portion of the output of said amplifier, a local oscillation generator, a frequency multiplier for frequency multiplying the output of said generator, apparatus for heterodyning a portion of the output of said frequency multiplier and another portion of the output of saidamplifier, apparatus for amplifying and filtering the output of said heterodyning apparatus, combining apparatus for combining the amplified and filtered output of said heterodyning apparatus and the output of said frequency divider, filtering apparatus coupled to the output of said combining apparatus, a converter for heterodyning together the output of said filtering apparatus and another portion of the output; of said frequency multiplier, a filter and amplifier coupled to the output of said converter, and a radiating antenna coupled to the output of said filter and amplifier.

18. A relaying system for relaying phase or frequency modulated Waves comprising an antenna for receiving modulated phase or frequency modulated waves, an amplifier for amplifying the waves picked up by said antenna, a series of frequency dividers for frequency dividing a portion of the output of said amplifier, a filler coupled to the final divider, a local generator, a frequency multiplier frequency multiplying the output of said local generator, a first converter in Which a portion of the output of said frequency multiplier and another portion of the output of said amplifier are heterodyned together, an amplifier and filter for amplifying and filtering the output of said first converter, a second converter in which the filtered output of the first converter and the ltered output of the last of said series of dividers is combined, a filter filtering the output of the second converter, a third converter in which the filtered output of the second converter and another portion of the output of said frequency multiplier are heterodyned` together, a filtering system for filtering the output of the third converter, and a radiating antenna coupled to said filtering system.

19. A radio relay system comprising a receiving antenna, an amplifier for amplifying waves received upon said antenna, a frequency divider for frequency dividing the output of said amplifier, apparatus for heterodyning the output of said frequency divider to a higher frequency, and

apparatus uitilizing the heterodyned Waves of higher frequency for re-transmission.

20. A radio relay system comprising a receiving antenna, an amplifier for amplifying Waves received upon said antenna, a frequency divider for frequency dividing the output of said amplifier, apparatus vfor heterodyning the divided waves to Waves of another frequency, apparatus for -heterodyning the heterodyned waves to a much higher frequency, a frequency multiplier for frequency 'multiplying said Waves to a much higher frequency, and a radiating antenna for radiating the frequency multiplied Waves.

21. A radio relay system comprising an antenna for receiving waves to be relayed, an amplifier coupled to said antenna, a frequency divider for frequency dividing the output of said amplifier, apparatus for successively heterodyning the output of said frequency divider with frequency divided Waves also derived from said amplifier but having higher and lower orders of frequency division respectively, filtering and amplifying Waves derived from the last heterodyning means, and utilizing the last-mentioned filtered and amplified Waves.

22. A radio relay system comprising a receiving antenna, an amplifier coupled to said receiving antenna, a frequency divider for dividing a portion of the output of said amplifier, a first converter to which said frequency divided Waves are fed, a frequency dividing system for frequency dividing to a high orderof frequency division another portion of the output of said amplifier, means feeding said highly frequency divided energy to said first mentioned converter, apparatus for filtering the output of said converter, a second converter to which said filtered output is fed, apparatus for dividing to a relatively small degrec a portion of the output of said amplifier, said output divided to a small degree being fed to said second converter, a second lter for filtering the output ofl said second converter, a frequency multiplier ycoupled to the output of said secondv filter, an amplifier and filter coupled to the output of said frequency multiplier, and a radiating antenna coupled to the output of said amplifier and filter.

23. A radio relay system comprising a receiving antenna, an amplifier for amplifying Waves picked up by said antenna, a frequency divider for frequency dividing a portion of the output of said amplifier, a converter in which an undivided portion of said amplifier and said frequencyv divided portion are combined, a filter and amplifier coupled `to the output of said converter, and a radiating antenna coupled to the output of said filter and amplifier.

24. An alternating current system comprising a receiving antenna, an amplifier coupled to said antenna, a frequency divider for frequency dividing a portion of the output of said amplifier, a series of frequency dividers for frequency dividing to a higher degree another portion of the output of said amplifier, a converter in which said divided energies are combined, a filter coupled to the output of said converter, and a utili zation circuit coupled to the output circuit of said lter.

25. A relay system for relaying phase or frequency modulated yWaves comprising a receiving antenna, an amplifier coupled to said antenna, a frequency divider for frequency dividing a portion of the output of said amplifier, a series of frequencydividers for frequency dividing to a higher degree another portion of the output of 9 said amplifier, a converter in which said divided energies are combined, a filter coupled to the output of said conver-ter, frequency multiplying, amplifyingand filtering apparatus coupled to the output of said filter, and a re-radiating antenna coupled to the output of said frequency multiplying, amplifying and filtering apparatus.

26. A radio relay comprising a receiving antenna, a series of frequency dividers for dividing down the frequency of a portion of Waves derived from angle modulated Waves picked up by said receiving antenna, circuits and apparatus forV reducing the mean frequency of another portion of waves derived from angle modulated Waves picked up by said receiving antenna, a converter for combining the output of the last divider of said series of frequency dividers and the output of the circuits, and apparatus for reducing the mean frequency yof waves derived from Waves received on the receiving antenna, a, filter and amplifier coupled to the output of said converter for transmitting and amplifying a, band of signaling Waves, and a retransmitting antenna for transmitting Waves derived from Waves transmitted by said filter and amplifier.

27. In combination, at a radio relaying station, a receiving antenna, an amplifier fo-r amplifying angle modulated Waves received upon said receiving antenna, a series of frequency dividers for frequency dividing a portion of the output of said amplifier, a converter for combining another portion of amplified waves derived from said amplifier with waves derived from an output circuit of said series of dividers, a filter for filtering the output of said converter so as to ytransmit a band of frequencies, and a transmitting antenna energized by Waves derived from waves transmitted by said filter.

HARRY TUNICK. 

